Internal-combustion engine.



G. S. OHAPIN. INTEENALYCOMBUSTION ENGINE.

APPLICATION PILBD SEPT. 26, 1910.

1,031,245. Patented July 2, 1912.

GARDNER S. CHAPIN, OF CHICAGO, ILLINOIS.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Application filed September 28, 1910.

Patented July 2, 1912. Serial N 0. 584,334.

To all whom it may concern.

Be it known that I, GrARDNER S. CHAPIN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Internal-Combustion Engines, of which the following is a specification.

Figure l is a transverse section on the line 1 of Fig. 2; Fig. 2 is a side elevation of the engine and Fig. 3 is a section on the line 3 of Fig. 2 looking downward, certain of the parts being shown in central-longitudinal sections.

Referring to the drawings, 10l0 are the cylinders of the internal combustion engine, the same having the usual working parts and being provided with valves of ordinary con struction. The intake valves may be automatic but they arepreferably mechanically operated in any usual Way, for reasons which will presently appear. 11 is a carbure'ter of ordinary form. Inter-posed be tween the carburetor and the intake valves of the engine is a pump-chamber 12, in which, in the preferred form of construction, are-two vanes 13 geared together and operating after the manner of the corresponding parts of any rotary-pump. The pump is directly geared to the engine in any obvious manner, its intake-end being connected to the carbureter 11 by pipe 14 and its exhaust-end being connected with the intake of the engine by an intake-manifold 15. The intake and exhaust sides of the pump are connected together by means of a bypass 16, in which is located a damper or valve 17. The pump is provided with a governor a form of which is shown in Figs. 2 and 8. In this governor one of the pumpshafts carries a sleeve 18 upon which is pivoted an angularly disposed ring 19, held in angular-relation by spring 20, which tends,"

as the pump shaft is rotated to assume a position at right angles to the axis of said shaft in an obvious manner.

The ring 19 is connected by links 21 with a sliding cap 22 on theendof the pump-shaft, the said cap being connected with a lever 23 the 0pp'osite end of which controls, through the medium of a link 24, the position of the ,damper or valve 17. The construction is i such that as the pump and en ine speed up,

the damper or valve Will be c osed.

The method of operation of my improved device is as follows: It has been found in practice that with engines such as are'used full charge is taken in at high speed. It.

has been estimated by a leading authority on automobile construction and practice, that under the usual running conditions, there is drawn through the intake-pipe of an automobile and passed into the cylinders only about one thirteenth of the volume of gas which could'be passed therethrough if the engine ran at so slow a. speed thatthe full displacement of the piston in cubic inches would be drawn in each time. This estimate may perhaps be too low, but there is no question but that in ordinary automobile practice a very small fraction-of the proper amount of mixture is drawn into the cylinder. This quantity decreases very rapidly as the engine speedsup, so that while at low speed, a comparatively large charge relative to the displacement of the piston may be drawn in, at high speed the charge is relatively low.

In the present device the pump is of such size and is driven at such speed as to maintain upon the intake valve of the engine a suflicient pressure at high speed to remedy to a great extent the present low charge. When the engine is running at high speed the governor holds the valve or damper 17 in the by-pass 16 closed, and therefore the full force of the pump is exerted to maintain this pressure. As the engine runs slower, the bypass is gradually opened so that the pressure upon the intake valve of the engine falls, until at the lowest possible speed it is maintained at little more than the ordinary atmospheric pressure.

I realize that it has been proposed in the past to provide pumping devices which would augment the charge of combustible mixture supplied to a gas engine. I am not aware, however, that means have ever, been provided whereby to increase the efi'ectivepumping action more rapidly than the engme speeds up. In the devices heretofore proposed, the pumps have been directly connected with the engine and if their capacity was greater than that of the cylinder, they pumped in an abnormally great charge at low speed and, of course, a relatively less one at high speed. In this device, however, the arrangement is such that at a low speed the charge is not augmented to any great extent but at high speed the augmentation becomes progressively greater.

I realize that considerable variation is possible in the details of the construction, without departing from the spirit of my invention; therefore I do not intend to' limit myself to the specific form herein shown and described.

What I regard as new and desire to secure by Letters Patent is- 1. In combination, an internal combustion engine, a source of combustible fluid,.means interposed between the engine and the source of combustible fluid for maintaining in the intake-pipe a gas-pressure above atmospheric-pressure, and means for increasing said pressure as the speed of the engine increases whereby substantially the full gaspressure may be delivered to the engine cylinder at all speeds of the engine.

2. In combination, an internal combustion engine, a source of combustible fluid, pumping means driven by the engine interposed between the engine and the source of combustible fluid for maintaining in the intakepipe a gas-pressure above atmospheric pressure, and means for increasing said pressure as the speed of the engine increases whereby substantially the full gas pressure may be delivered to the engine cylinder at all speeds of the engine.

3. In combination, an internal combustion engine, a source of combustible fluid, means interposed between the engine and the source of combustible fluid for maintaining in the intake-pipe a gas pressure above atmospheric pressure, and automatic means governed b the speed of the engine for increas-' ing sai pressure as the speed of the engine the speed of the engine increases, whereby substantially full gas pressure may be delivered to the engine cylinder at all speeds of the engine.

5. In combination, an internal combustion engine, a source of combustible mixture, pumping means driven by the engine and interposed between the same and the source of combustible mixture, a bypass around the pump, and means by which the eflective area of the by-pass may be decreased .as the engine speeds up.

6. In combination, an internal combustion engine, a source of combustible mixture, pumping means driven by the engine and interposed between the same and the source of combustible mixture, a by-pass around the pump, governor controlled means for decreasing the effective area of the by-pass as the speed of the engine increases.

7 In 'an internal combustion engine, means for maintaining a gas-pressure in the intake-pipe above the atmospheric-pressure and for increasing said pressure as the speed of rotation of the engine increases.

GARDNER S. CHAPIN.

In the presence of- J Gr. ANDERSON, R. A. SOHAEFER. 

